1. Field of the Invention
The present invention relates to an ostomy appliance comprising an adhesive, flexible skin barrier product for securing the appliance to the user""s skin said barrier having a hole for receiving a stoma, ureter or catheter and barrier wafer showing improved capability of undergoing deformation owing to the user""s movements, an adhesive flexible skin barrier product for use as a semi-manufacture in the production of dressings, skin and wound care devices, fastening means for wound care devices, fastening means for dressings, ostomy equipment, wound drains and incontinence equipment such as external catheters and for similar applications and for use in electrodes for application to the skin; and the use of a starch for modifying of the absorbing and rheological properties of the first zone of an adhesive, flexible, skin barrier product layer for an ostomy appliance comprising at least a first zone showing adhesive and barrier properties and a second zone showing moisture absorbing properties.
In connection with surgery for a number of diseases in the gastrointestinal or urinary tract a consequence is, in many cases, that the colon, the ileum or the ureter has been exposed surgically and the patient is left with an abdominal stoma, or, in nephrostomy or ureterostomy, the ureter or a catheter is exposed in the back or the chest region or abdominal region, and the effluents or waste products of the body, which are conveyed through these organs, are discharged through the artificial orifice or opening and are collected in a collection bag, which is usually adhered to the skin by means of an adhesive wafer or plate having an inlet opening for accommodating the stoma/ureter/catheter. Also in connection with a fistula, the patient will have to rely on an appliance to collect the bodily material emerging from such opening.
2. Description of the Related Art
Ostomy appliances are well known. Such appliances may be two-piece or one-piece appliances. In both types of appliances, an adhesive barrier member (or base plate) is attached to the wearer""s abdomen/back/chest. In case of a one-piece appliance, a receiving member or bag is attached to the adhesive barrier. In case of a two-piece appliance, the adhesive barrier member forms part of a body side ostomy member and a receiving member or bag is attached releasably to the body side member for receiving exudates from the stoma.
When using one-piece appliances, the whole appliance, including the adhesive skin barrier securing the appliance to the skin is removed and replaced by a fresh appliance. When using two-piece appliances, the body side member is left in place up to several days, and only the receiving member or bag attached to the body side member is replaced. The attachment means for attaching an ostomy receiving bag may be a system known per se comprising matching coupling rings or matching flanges and adhesive surfaces engaging with and sealing against a flange area of the body side member.
For two-piece appliances, the service time of the body side member depends on the amount and aggressiveness of the exudates and of the tightness of the sealing between the stoma and the body side member.
In such a collecting system, the adhesive skin barrier of the body side member must be able to remain on the user over a long period of time, for example up to 8-10 days in order to minimise the irritation of the skin due to removal of the adhesive skin barrier, cleaning of the area and application of a fresh appliance. Users engaged in active employment prefer to have the option of exchanging the body side member only on a weekly basis for convenience.
WO 89/05619 and WO 94/15562 disclose skin barrier products comprising two or more essentially non-mixed materials having different properties. When using adhesive compositions designed to provide barrier properties, adhesiveness and grip for securing the skin barrier product to the skin, and adhesive compositions designed to provide moisture absorptive properties, respectively, the adhesive barrier part is often based on a material with very low or no absorbing properties which is often a relatively soft and tacky material whereas the moisture absorbing composition is relatively hard.
In the above system considerable differences in Theological properties will often be found between the moisture absorbing adhesives and the adhesives showing barrier properties. These differences in rheological properties are due to different formulations of the two adhesives, and especially the difference in content of hydrocolloids plays an important role. A comparison of a moisture absorbing adhesive and an adhesive having barrier properties wherein the proportions of polymer constituents, resins, plasticizers and oil are the same for both adhesives, but 40-60% hydrocolloids has been added to the moisture absorbing adhesive whereas the adhesive having barrier properties comprises no or only 5-10% hydrocolloids, shows that the moisture absorbing adhesive will appear harder (less elastic) than the adhesive having barrier properties.
In order to improve the service time and security against leakage the body side member must be capable of undergoing deformation owing to the user""s movements, washing, exposure to bag replacements, etc. Conventionally, the base plate of such a carrier device is designed as a thin adhesive foil, optionally with some sort of stiffening reinforcement disc for maintaining a plane adhesive surface for the bag.
If the above types of adhesives are used in the systems disclosed in WO 89/05619 and WO 94/15562, the advantages disclosed therein will naturally be obtained with respect to spreading of absorbed water in the system. The spreading will naturally be minimised due to the barrier layer which, again, will lead to a minimising of the leaching. Considerable differences in rheological properties of the different zones of the base plate product may, however, give rise to processing problems and may cause skin problems on the user.
The process problems will be most pronounced when cutting the blank base plate products and during a later bevelling or contouring and punching of the product. A considerable difference in the hardness of the different zones may render the cutting process difficult as the structure of the products disclosed in WO 89/05619 and, hence, the desired properties, may be disturbed if the material is not kept sufficiently cold. During bevelling or contouring, the rheological differences between the different zones may cause the soft adhesive to be pressed over the harder adhesive at the surface to be in contact with the skin and this will of course disturb the design properties of the product and may cause problems for the patients.
Another problem which may be caused in a system disclosed in the patent applications referred to above due to the rheological differences is a mechanical stressing of the skin as the two adhesives function very differently. The soft barrier adhesive will easily be able to follow very small movements of the skin whereas this is not the case for the moisture absorbing adhesive. It may be compared to pinching the skin and may be experienced as itching when the adhesive is placed on the skin and a light reddening after removal.
Thus, when the patient moves or bends, the difference in rheological properties of the different materials may even give rise to lack of contact between the two materials. This may cause irritation due to opening and closure of small cracks in the surface of the skin barrier product which may cause direct physical irritation or reduce the time of service during which the skin barrier product is able to protect the skin against contact with the exudates from a stoma.
It is an object of the invention to eliminate these problems by rendering the different adhesives rheologically more alike.
Normally it is not possible to render the adhesive comprising hydrocolloids more soft without loosing the high absorption capacity.
The adhesive showing barrier properties must not be amended in a manner giving pronounced change of the barrier properties of the adhesive as this property is of great importance for the performance of the system. By addition of hydrocolloid it is possible to obtain the desired Theological properties but then, the adhesive will be absorbing when in contact with moisture leading to a loss of the barrier properties.
A change of the proportion between the polymer constituents, resins and plasticizer will cause a shift of the ratio between the viscous and elastic moduli of the adhesive which is undesirable.
It has now been found that it is possible to add a constituent with an inherently low water absorbing capacity which makes the barrier adhesive, in a dry state, xe2x80x9cbehavexe2x80x9d Theologically as an adhesive comprising hydrocolloid but which does not swell in the presence of moisture. Furthermore, it has been found that it is possible to provide a barrier layer comprising hydrocolloids and showing low absorption and being Theologically similar to conventional moisture absorbing adhesives comprising hydrocolloids.
The present invention relates to an ostomy appliance comprising an adhesive, flexible skin barrier product for securing the appliance to the user""s skin, said skin barrier having a hole for receiving a stoma, a ureter or a catheter and said skin barrier comprising, in the surface to be secured to the user""s skin, at least a first zone showing adhesive and barrier properties and a second zone showing moisture absorbing properties.
Furthermore, the invention relates to an adhesive flexible skin barrier product for use as a semi-manufacture in the production of dressings, skin and wound care devices, fastening means for wound care devices, fastening means for dressings, ostomy equipment, wound drains and incontinence equipment such as external catheters and for similar applications and for use in electrodes for application to the skin.
Still further, the invention relates to the use of a starch in an amount of from 2 to 85% by weight for modifying of the Theological properties of a zone of an adhesive flexible, skin barrier product layer for an ostomy appliance comprising at least a first zone showing adhesive and barrier properties and a second zone showing moisture absorbing properties, said zone comprising a substantially homogeneous mixture of from 15 to 98% by weight of one or more rubbery components and furthermore may comprise from 0 to 60% by weight of one or more hydrocolloids, from 0 to 50% by weight of one or more tackifier resins, from 0 to 10% by weight of one or more plasticizers and from 0 to 5% by weight of a pigment.